Highly strained AlAs-type interfaces in InAs/AlSb heterostructures

Maxime Vallet (1, 2) , Yann Claveau (2, 1) , Bénédicte Warot-Fonrose (3) , Christophe Gatel (3) , Julien Nicolaï (2, 1) , Nicolas Combe (1) , C. Magen (4) , R. Teissier (5, 6) , A. N. Baranov (5, 6) , Anne Ponchet (2, 1)

1 CEMES-SINanO - Surfaces, Interfaces et Nano-Objets
2 CEMES - Centre d'élaboration de matériaux et d'études structurales
3 CEMES-I3EM - Interférométrie, In situ et Instrumentation pour la Microscopie Electronique
4 Universidad de Zaragossa
5 IES - Institut d’Electronique et des Systèmes
6 NANOMIR - Composants à Nanostructure pour le moyen infrarouge

Spontaneously formed Al-As type interfaces of the InAs/AlSb system grown by molecular beam epitaxy for quantum cascade lasers were investigated by atomic resolution scanning transmission electron microscopy. Experimental strain profiles were compared to those coming from a model structure. High negative out-of-plane strains with the same order of magnitude as perfect Al-As interfaces were observed. The effects of the geometrical phase analysis used for strain determination were evidenced and discussed in the case of abrupt and huge variations of both atomic composition and bond length as observed in these interfaces. Intensity profiles performed on the same images confirmed that changes of chemical composition are the source of high strain fields at interfaces. The results show that spontaneously assembled interfaces are not perfect but extend over 2 or 3 monolayers.

Domaines: Physique [physics]

Maxime Vallet, Yann Claveau, Bénédicte Warot-Fonrose, Christophe Gatel, Julien Nicolaï, et al.. Highly strained AlAs-type interfaces in InAs/AlSb heterostructures. Applied Physics Letters, 2016, 108 (21), pp.211908. ⟨10.1063/1.4952951⟩. ⟨hal-01707044⟩